👋 Hi, I'm Sieun Lee

📍 Based in Seoul
🚀 Curiosity-driven Web Developer, who enjoys exploring new technologies and deep-diving into framework internals.

Featured Projects & Engineering

ecommerce-be E-COMMERCE BACKEND

Scalable architecture reflecting large-scale system design.

lifepuzzle-rn CROSS-PLATFORM APP

Mobile frontend for intergenerational story archiving.

zion-web INFRASTRUCTURE

Self-hosted automation and server infrastructure.

Latest Blog Posts

• Claude API 토큰 효율 높이기
• Claude API를 서비스에 붙이면서 — 스트리밍, 시뮬레이션 제어, 토큰 절약
• Claude API
• 증권거래소- Matching Engine 구조 정리
• MCP 구조 분석 - Orchestration Layer

Open Source Contribution

Spring Data JPA

• Modernizing Query Parsers for Jakarta Persistence 4.0
  • Refactored ANTLR4 parser definitions (Jpql.g4, Eql.g4) to support optional ELSE clauses in CASE expressions.
  • Resolved technical mismatch between persistence providers (Hibernate 6+) and the abstraction layer.
  • Successfully merged and backported to maintenance versions.

Links

💡 "Deeply understanding the tools we use is the first step toward true engineering excellence."